This invention relates specifically to the field of ophthalmic surgical handpieces. More particularly this embodiment relates to an apparatus and method for detecting the presence of an ophthalmic surgical handpiece which is electrically isolated from ground and the power source.
The use of ultrasonic handpieces or probes for the removal of cataracts from the human eye is well known. Typically, this procedure, called phacoemulsification or phacofragmentation, uses ultrasonic probes for rupturing cataracts in the eye combined with aspiration of the resulting debris. Ultrasonic phacoemulsification probes conventionally include a piezoelectric crystal(s) affixed to the probe body. The crystal is driven by an electric power source and it converts the electric power to ultrasonic power which is applied by the probe to the eye. The amount of power applied by the probe is a function of the frequency and amplitude of the driving electrical waveform and it is typically under control of the surgeon using the probe.
Prior art circuits for phacoemulsification probes have operated in a grounded patient configuration. The prior art circuits have included an apparatus for sensing the presence of the phacoemulsification handpiece or probe, but the handpiece and the sensing apparatus have been connected to ground.